around here, spring sales happen early. A few years back I replaced my very old , 30yr old , sleeping bag, which was reasonable for weight, but a bit narrow always (mummy style) and not great for cooler temps.
On sale for about $200 I got a down camping quilt rated to 0c 32f, and about half the weight of my old bag, but realistically as an old skinny guy I need to bundle up a lot nearer to those temps--but also realistically very rarely am bike camping at those temps.

years ago I also replaced my campmat for one that weighs about a pound,

all these things are worth it to me as others have said for the enjoyment factor in life, less weight a real bonus, and I am frugal also.

re weight, I cant recall if you are a CPAP machine guy also, but 50lbs is a lot. Who knows what other stuff you bring along on a bike trip, and pretty much impossible for us to know, or to compare what one person finds essential vs another person.
For those of us who have bike toured a long time, and/or done other self propelled outdoor activites, the vast majority have learned over time by trial and error how to pare down things, but still be comfortable, but this is a purely personal thing--and I have friends who cannot fathom traveling with so few things--but really, I'm a skinny guy who hates being cold, so I make sure I am comfortable for a wide range of temps, but I can also live happily with few things on my bike, so that helps a lot.

I grew up doing canoe camping, so this helped a lot in learning to be very efficient in what to take, clothes, camp stove, cooking stuff etc.

good luck on examining your pack list and reducing the weight of specific items (a very valid thing to do, as your sleeping bag shows) but also looking at the overall picture.